"At this moment, we don't have any information that would indicate that the plane has either crashed or made an emergency landing," Jose Gomes Ferreira, a spokesman for Brazil's Aeronautical Command told Globo television Saturday.

Earlier, Defense Minister Waldir Pires said the Legacy was seriously damaged in what appeared to be a collision. "The collision was, presumably, with the GOL Boeing," he told Bandeirantes television.

But the National Civil Aviation Agency (ANAC) said there was no evidence to support that "hypothesis."

"It is not possible to state that there is a link between the incident that forced the crew (of the Legacy) to make an emergency landing at the Cachimbo airport and the disappearance of the GOL aircraft," ANAC said.

Dozens of anxious relatives and friends of those missing gathered at the airports of Brasilia, Rio de Janeiro and Manaos seeking information about their loved ones.

The Boeing was reported missing Friday in a densely forested area 200 kilometers south of Cochimbo.

"Landing there would be a high-risk operation, but amazing things can happen in aviation, so we keep hoping," said Jose Carlos Pereira, president of the Infraero company that runs Brazilian airports.

Officials said there were 149 passengers and six crew members aboard the GOL airliner.

Two Radiobras journalists, three aviation officials and several staffers of the Aeronautics Ministry were among the passengers, according to ANAC.

As airborne search parties searched for the missing jetliner during the night, dozens of relatives of the missing passengers and crew rushed to Brasilia's airport hoping to get information about the fate of their loved ones.

Civil aviation authorities said Flight 1907 of the GOL discount carrier was reported missing several hours after leaving the Amazonian city of Manaus on Friday, on a flight headed to Brasilia and then on to Rio de Janeiro.

Brazilian Air Force planes and helicopters headed to the crash area, using infrared equipment to look for signs of the missing jetliner, searchers waited for daylight to conduct a visual search.

Local hospitals were put on full alert.

Created in 2001, GOL is Brazil's leading discount carrier. Its 53 planes service some 50 domestic destinations as well as neighboring Paraguay, Uruguay, Argentina, Bolivia and Chile.

Brazil's deadliest air accident occurred in June 1982, when 137 people were killed as a Boeing 727 of the VASP airlines crashed against a hillside as it prepared to land in the northeastern city of Fortaleza in June 1982.

The occupants of the Legacy were unharmed after the emergency landing, according to Embraer, the aircraft's Brazilian manufacturer. Local media said the plane was to be delivered to a US client.

With almost 90 percent of the ballots counted, Lula garnered 49.28 percent of the votes, while his opponent, former Sao Paulo Governor Geraldo Alckmin, got 40.95 percent.

Vote counting is delayed in Sao Paulo, Brazil's most populous state, where polls indicated that Alckmin led the presidential race. That means it is still unclear whether Lula will be re-elected in the first round.

Lula has to win more than 50 percent of the votes to win outright on Sunday and avoid going into a runoff on Oct. 31.

The polls opened on Sunday for some 126 million eligible voters to elect a president, 513 federal representatives, 27 senators, 27 state governors and 1,059 state deputies.

Lula, 60, had enjoyed a comfortable lead in previous opinion polls, but his support dropped in the last days of campaigning amid public anger over a scandal involving members of his party.

A former trade union leader, Lula is highly popular among millions of impoverished Brazilians, largely thanks to his administration's emphasis on social programs aimed at narrowing the country's enormous income gap.

Alckmin, a 53-year-old physician, is favored by the business community and wins support from middle class Brazilians who are outraged by a series corruption scandal involving close aides of Lula.

Alckmin officially announced his presidential candidacy in March 2006, and secured a second place in previous opinion polls. He was attempting to gather the necessary votes to force a run-off with Lula.

Dolly the sheep made headlines around the world in 1997 because she was the first mammal to be cloned from an adult cell -- a cell taken from a grown animal. Animals had been cloned using cells from fetuses and embryos, but not grown animals.

But some scientists argued that truly mature tissue is too old to be re-generated, and that Dolly and the hundreds of cloned cattle, pigs and other creatures that followed here were in fact created using stem cells or stem-like cells by accident.

These master cells of the body retain an ability to form various tissues, and they are not always easy to pick out from the cells around them.

Dr. Jerry Yang of the University of Connecticut noted that cloning is still very difficult to do. Only about 2 or 3 out of 100 tries generally works.

"This was seen as circumstantial evidence that it was stem-like cells that succeeded in cloning," Yang said in a telephone interview.

"The question is important because the success rate for reproductive cloning is still quite low."

Yang, Dr. Tao Cheng, of the University of Pittsburgh, and colleagues cloned mice using fully differentiated, or mature, white blood cells called granulocytes.

Writing in the November issue of Nature Genetics, they said they used somatic cell nuclear transfer, in which the nucleus from a cell of the animal to be cloned is injected into an egg whose nucleus has been removed.

This process works very poorly in mice and usually a two-step procedure is needed -- first growing tiny embryos, then removing their embryonic stem cells to generate mouse pups.

Yang's team tried cloning using the blood cells at various levels of development -- from the stem cells stage through full maturity, called full differentiation.

"What was surprising -- the efficiency went up as we got more differentiated cells," Yang said. "That was very, very surprising, very shocking to us."

Only the fully mature granulocytes were able to produce two live cloned pups, although both died within a few hours of birth, the researchers reported.

"Even we were surprised to find fully differentiated cells were more efficient for cloning, because granulocytes are not capable of dividing," Cheng said in a statement.

"In fact, we repeated our experiments six times just to be sure. Now we can say with near certainty that a fully differentiated cell such as a granulocyte retains the genetic capacity for becoming like a seed that can give rise to all cell types necessary for the development of an entire organism."

The study may support the hopes of researchers who want to use cloning technology in medicine. Supporters of so-called therapeutic cloning want to some day be able to take a single cell from a patient, perhaps a skin cell, and use it to generate tailor-made tissue or organ transplants.

To do so, fully mature cells must maintain the ability to regress in this way and be reprogrammed.